Safety switch box



Jam., 2, 1923,

O, S, JENNINGSy SAFETY Swl TCH Box 2 SHEETS-SHEET I F| LED Nov 2O l 920. v

NVENTCR Patentedgdano 2,

OLIVER S. JENNNGS, F BROCBKLYN, NEW YORK, ASSEGNOE, TG WESTENGHGUSE SAFETY SW'TCH BOX.

application nee november 2o, 1920. serial no. 425,525.

T 0 ali whom it may concern: l

Bie it known that l, @Livra S. JENNINGS, a

y a citizen of the yUnited States, and' a resident of Brooklyn, in the county of Kings and State of New York, have invented av new and Iuseful improvement in lSafety Switch Boxes, of-whiehthe following is a specification.

My invention relates to switch mechanism and particularly to switch 'mechanism ofthe brush type wherein a switch brush is pivotally mounted within a housing and engages i contact members disposed y adjacent tothe.

switch base and to the front o the housing.

The outer contact members 'of switches of this type are usually mountedI upon the cover. While this construction has many advantages, one of them being tha-tithe switch may be inspected without diiiculty when the cover is open, it is not possible, when the cover is closed, .to determine whether the switch isl in proper enga-gement with the contact members onv the cover.

An object of my invention is to provide a' switch mechanism of the general type above referred to wherein the outer. contact member is supported upon a base member which su ports the (switch, instead of on the cover. y mounting .the switch. and. contact members upon the detachable base, the switch mechanism constitutes a unit which may be removed bodily from' the housing for the purpose of inspection and repair.

Another object ot the invention ist/o provide a switch mechanism, having theabove characteristics, wherein the operating mechaf nism' for the switch constitutes a complete unit that is entirely independent ol' the switch mechanism and permits the removal of the switch mechanism v vithout interference with the operating mechanism.

,1h-further object of the invention provide a switch mechanism having ali is to of with the ladded advantage of the unit construction without complicatingy the struc-1 tureand without increasing the manufacturingcost thereof. i

A kfurther object rovide a switch structure that 'may be keyactuated, thereby precluding the operation thereof by unauthorized persons.

A. further object ofthe invention is to provide a unit-switch construction with an independently-mounted mechanism that will bruslrtype switch ot' the invention is tol impart snap action tothe switch mechanism.

These and other objects, that will he apparent throughout the further description ofthev invention, are attained by means of 4the switch mechanism hereinafter described and illustrated in the accompanying drawings, wherein:

vFigure 1 is a plan view of the switch mechanism mounted within a housing having the cover removed.

v Fig. '2 'isl a longitudinal section of the housing taken on the line lle-1l of Fig; 1, showing portions of the switch mechanism in section and in side elevation.

-Fig. 3 is a transverse section through the housing taken on the line lill-H1 of Fig. 2. Fig. f1 is a perspective view of a portion of the operating handle.

l4`ig. is a fragmentary elevation 'of cer tain switch-controlling elements, showing their relative positions when the switch is in open position, and

Figs. 6 and 7 are perspective views of de tails -of the switch mechanism.

Referring to the drawings, theapparatus includes a housing having a bottom wall 7 andl side and end walls 8 and 9, respectively. The housing is provided with a detachable cover 11 thatis preferably secured to'the housingby meansot screws 12.A

The switch mechanism includes an insulating base or panel 13 that is detachably secured to the bottom wall 7 by means of screws 111. Upon opposite sides of the base, a pair of separate supporting standards or plates 15 and 16 are secured by means of bolts 17.

The switch member 18 is pivotally mounted between the supporting plates upon a shaft 19 that is rotatably supported by the supporting plates., The switch is of the brush type and consists of a `plurality of metal strips that are clampedbetweenl plates 21 which are secured to the switch shaft 19.

A contact plate 22 is mountedupon one end of the base 13 and is conductively attached to the live terminal 23.

Spaced from the opposite end of the panel p contact members 22 and 24 and is movable from the closed position shown in full lines in Fig. 2 to the`open position shown in broken lines in the same figure. rllhe switch is turned through the medium of two bellcrank levers 27 that arel secured 'to opposite ends of the shaft 19. The levers are normally yieldingly held in open position by means of tension springs 28 that are attached at one end to the supportingl plates 15 and 16 at 29 and, at the other end, to the arms 31 of the cranks 27.

The switch member 18 is retained in closed position by means of a pair of toggle links 32 and 33, the former being pivoted to the arm 34 of the crank 27 by means of a pin 35 while the latter is pivoted to the auxiliary shaft 36 that is mounted onv they supporting plates 15and 16. *i l The knee-pivot pin 37 connects the toggle links and operates in an,4 arcuate slot 33 that is disposed in the supporting plate 16 concentric to the axis of-the shaft 36. 'When the toggle links arein the position indicated in Fig. 2, the knee-pivot pin'occupies a position on one side of the dead centerof the toggle and bears against the lower end of the arcuate slot. V j y The switch ;will, therefore, remain ,f in closed position until the pinI 37 is moved to the other side of the dead centerfof the toggle, at which time the toggle will collapse and permit the switch to move to the open position indicated in broken lines in Fig. 2. At this time, the pivot pin 37 is held, against the upper end of the slot-'38 'rliich serves to limit the opening movement of the switch.

It will be understood that the switch-controllin and actuating mechanism just describe is duplicated on the side of the apparatus adjacent to the plate 15, and, therefore, the switch yshaft is actuated by a forcel exerted at each end of the shaft.

rEhe switch mechanism above described is constructed and assembled as a unit and may shaft is provided with notches 41 adapted to receive a handle 42 (Figs. 2, 4 and 5) that is provided with a forked key portion which is so slotted that it itsinto the notches 41. The housing 43,` that is provided with an opening 44 for the entrance of the handle,

. serves to protect the outer end of the operating shaft and prevent its manipulation excelpt by means of the proper key handle. T

e slots 41 are so disposed with relation to the switch and the opening 44 that the key cannot be moved While the switch is in closed 'position The inner end of the-operating shaft 39 is provided with a pawl lever 45 (Figs. 1, 5

and 6) having contact faces 46 and 47 that are adapted to-overlap the projecting end of the pin 37 carried bythe toggle links and engage the opposite sides thereof.

vA spring shaft 48 is pivoted to the ar-m of the lever 45 by means of a pin 49, and the free-end thereof is slidably mounted in a guide bracket 51 that is secured to the side of the housing. A compression spring 52 surrounds the shaft and is dis posed between the shoulder 53 and the guide bracket 51. The springs serve to yieldingly retain the operating shaft 29 in either open or closed position and to move it to open or to closed position I.with a snap action when the pivot pin 49 passes the center line connecting the axis of the shaft 39 and the opening in the guide bracket 51 through which the shaft 48 projects.

Assuming the switch to be in the closed position'shown in Fig. 2, the operation is as follows The keyl portion of the handle 42 is inserted through the opening 44 in the housing 43. into engagement with the notched portion of the operating shaft 39.

move the knee-pivot 37 upward from made position when the contact face 46 of the lever 45 engages the projecting end of the pin.

The `handle is then turned downward and will When the pin 37 is moved upward past4 the dea-d center ofthe toggle, the toggle will collapse to broken position in response toi the.. action of thesprmg` 28, which will turn the switch to open position with a snap action. The space between the contact faces 46 and 47 of action. K I

To'close the switch, the handle is moved upward, thereby moving the contact face 47 into engagement with the pin 37. When the pin 37 is moved past the dead center of the toggle', the latter will hold the switch in closed position against the tension of the spring 28. The spring 52 serves, at thistime, to retain the operating shaft in closedI position.

It will be apparent from the foregoing that there 'is a lostmotion connection between the switch-operation mechanism and the switch unit, and that the switch unit may be removed bodily fromvthe housin without interference with'the switch mec anism.

While l have described and illustrated but 4 the lever 45 permits. of this one embodiment of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions,

-as set forth in the appended claims.

l claim as myl invention: 1. ln switch mechanism enclosed within a covered housing, the combination with a 130v L intona? movable switch member supported upon a detachable base and operating between separate contact members secured to the base, ot' an operating means mounted ena lined wall of the housing and detachably engaging the switch member tor permitting removal of the switch member independently ot the operating means.

2. ln switch mechanism enclosed within a covered housing, the combination with a movable switch member supported upon a detachable base and operating between separate Contact members secured to the base, et an operating means mounted on a xed wall of the housing for imparting a snap-action openingv and closing movement to the switch member and detachably engaging the switch member for permitting removal of the switch member independently oit the operating means.

3. Switch mechanism comprising a housf ing, a detachable base member within the housing, a pair of support members mounted on thevbase member, an outwardly lacing contact member mounted on the base member, an inwardly facing contact member mounted on the support member, a switch member pivotally mounted on the support member and movable into contact with the Contact members, and means mounted on the housing independently of the switch member, detachably engaging the switch member for imparting opening and closing movement to the switch member.

d. Switch mechanism comprising a housing, a base, member. termtinal members mount= ed thereon, a vswitch member mounted on the base member tor connecting the terminal members and movable to open and closed positions, yielding means for normally moving the switch member to open position, toggle links for retaining the switch member in closed position when the links are in made osition, and means mounted on a fixed wall ot the housing for actuating the toggle links and detachably connected thereto whereby the switch member may be removed from the housing independently ot the said actuating 5. Switch mechanism comprising' a housing, a base member, terminal members mounted thereon, a switch member mounted on the base member for connecting the terminal members and movable to open and closed positions, yielding means tor normally moving the switch member to open pou sition, releasable means for retaining the switch member in closed position, and means mounted on a fixed wall ot the housing tor and to closed positions, yielding means tor' i normally moving the switch member to open positiom-and a releasable means or retaining the switch member in closed position having a portion detachably connected to the said switch-actuating means and adapted to be actuated thereby.

: 7. Switch mechanism comprising a housing, a movable switch-'member within the housing, an operating shait tor the switch projecting exteriorly ot the housing and hav'- ing a key-receiving portion, an auxiliary housing for enclosing the key-receiving por tion provided with a key slot for permitting limited angular movement ot the hey about the axis of the shaft and adapted to engage the key and prevent removal thereof when the shaft is in a predetermined position.l

ln testimony whereof, ll have hereunto subscribed my name this fourth day of Nov. 1920.

@LlVER S. JENNNGS. 

